Keyboard music instrument



Sept. 9, 1930. STOEHR 1,775,330

KEYBOA'RD MUSIC INSTRUMENT Filed May 31, 1924 Q I INV TOR u v 71m, $214A} BY 437 ATTORNEY Patented Sept. 9, 1930 UNITED STATES monrz s'ronrm,or naw'roanar. r.

KEYBOARD MUSIC: ms'rnunnn'r Application filed May 31,

My invention has reference to pianos and similar keyboard instruments,and the object of my invention is to produce a keyboard instrument whichis equipped with two string- 6 frames whereby the number of stringsusually formed in such an instrument is doubled.

The strings of the second string-frame are tensioned so as to be alittle higher pitched than the strings of the usual string-frame, so

1 that an instrument is obtained on which quarter-tones can be produced,while on the keyboard instruments now in use as is Well known, onlyhalf-tones can be produced. In combination with the second string-frame,

there is, of course, provided also a separate set of hammers, and thesehammers are operated by keys of a special keyboard, wh1ch is preferablyarranged somewhat above and behind the keys of the usual keyboard. The

instrument thus is a double keyboard instrument.

For a better understanding of my invention I refer to the accompanyingdrawing in which the invention is diagrammatically illustrated and inwhich Fig. 1 shows the two string-frames arranged one behind the other;

Fig. 2 is a side view of the two string-frames showing also thehammer-action and the keys cooperating therewith; Fig. 3 is a top-viewof the double keyboard, Fig. 4 shows the disposition of the keys of thetwo keyboards on an enlarged scale; Fig. 5 shows a modification in therelative position of the two stringframes.

In the preferred embodiment of my ,invention, I arrange the twostring-frames 1, 2 parallel to each other, one behind the other, therear string-frame being elevated relative to the front string-frame soas to enable the hammers 3 to strike the strings as shown in Fig. 2. Thesounding boards and other parts of the instrument have been entirelyomitted as not forming any part of this invention. In fact, except forthe addition of the second string-frame, the second set of hammers andthe additional row of keys, the construction of the instrument is notchanged in any particular.

The strings drawn across the front stringframe, which is the usualstring-frame, are

1924. Serial No. 716,864.

struck by the hammers 4 2) which-are operated in the well-known manner,*by means of-thehammer-action;5 by the white or black keys 6 and 7respectivelyofthe ordinary keyboard 8 (Fig.3). "Thehammersj3,intended255 to strike the strings of'the rearstring-fra-me,

are operated by-means of the hammer action 9 bythe white and black keys.IO-and 11 respeetively of theupper keyboard 12. As shownin'Fig. '2,thekeys of the uppeflkeyboard are preferably slightly inclinedtowardthekeys of the lower keyboard-to-facilitate their manipulation. 13,114and-15 designate the rails provided -'for-:the keys of'the-twokeyboards. Fig. 4 shows the {relative arrangement-of: the keys of thetwo-keyboards on a larger scale. p

Asshown in Fig. '3,- the keysof =theupper keyboard 12 are slightlyofisetrelative to the keysof the lower keyboard8*to-therehy indicate thatthe strings set in vibration {by the depression ofthe keys ofgthe'upperkey board are pitcheda little higher thanethe strings set invibrationby 1 the trays: ofthe lowerikeyboard. iIn the present instance,3 referring to an upri ht piano, the diflerence between the pitch 0% thestring corresponding say to the key C of the upper keyboard is aquarter-tone higher than the pitch of the string corresponding to thesame key in the 410 lower keyboard, and so on, throughout the entirerange of keys. Thus, the chromatic range of the tones capable of beingproduced by such a piano, in accordance with the present invention isdouble that of an ordinary piano, on which by the use of the black keysonly half-tones can be produced.

As the keys are arranged in two separate keyboards controlling separatesets of hammers, anyone desiring to do so can play the piano like anyother piano by using only the keys of the lower keyboard 8. By theaddition of the upper keyboard, 12, the second set of hammers therebycontrolled and the second string frame, a keyboard instrument isproduced, which in variety of tones and tone-combinations approaches astring instrument, such as a violin or violin-cello, on which theroduction of tones is varied by the position of the fingers of theperformer.

Instead of arranging the two string-frames parallel to each other asshown in Fig. 2, the string-frames may also be arranged as indicated inFig. 5, where the rear stringframe 2 is shown at an angle relative tothe front string-frame 1.

In the actual manufacture of such van instrument other changes mayrecommend themselves which do not affect the essence of my inventionwhich I claim:

1. In a keyboard music instrument, the

combination of two relatively displaced string-frames arranged onebehind the other, two separate sets of hammer actions disposed in frontof the first string frame, two separate keyboards each comprising a fullset of black and white keys, and separate mechanisms for transmittingthe movements of-the keys of each keyboard to the hammers of thecorresponding hammer action.

2. In a keyboard music instrument, the combination of two relativelydisplaced string-frames, one behind the other, and the second framebeing higher than the first frame, two separate sets of hammer actionsdisposedin front of the front frame, two separate keyboards arranged interrace Jiorm and each comprising a full set ofblack and white keys, andseparate mechanisms for transmitting the movements of the keys of eachkeyboard to the hammers of the corresponding hammer actions. v 7' 3. Akeyboard'instrument as set forth in claim 1, in which the keyboard forthe rear string-frame is elevated relative totheother keyboard and thekeys of said elevated keyboard are oflset relative to the keys of theother keyboard In testimony whereofI aflix my, signature.

MORIZ STOEHR. 1

